Oxidation and reduction: losing and gaining electrons
Grade 10 Science Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
In a battery, 5 zinc atoms each lose 2 electrons to become Zn²⁺. How many electrons are lost in all, Ari?
4 aluminum atoms each lose 3 electrons to become Al³⁺. How many electrons are lost in all, Bo?
As a nail rusts, 6 iron atoms each end up losing 3 electrons, becoming iron(III). How many electrons are lost in all, Esme?
Using the tally, what does the Cu²⁺ ion become, Luz?
- Copper metal
- Zinc metal
- A Cu⁴⁺ ion
What is oxidation, Milo?
- Losing electrons
- Gaining protons
- Gaining electrons
What is reduction, Noah?
- Losing electrons
- Gaining electrons
- Losing some of its mass
Why do oxidation and reduction happen together, Pia?
- Lost electrons must go somewhere
- Atoms cannot be split into pieces
- Oxygen must be present
What is the oxidation number of a pure element, such as Fe or O₂, Ren?
- 0
- +1
- −2
What oxidation number does oxygen usually have in compounds, Tala?
- −2
- +2
- 0
What is the oxidation number of sodium in NaCl, Zee?
- +1
- +2
- −1